The Mortgage Works’ (TMW) buy-to-let affordability calculator app is now available to Apple iPhone and iPad users.

The Android and BlackBerry versions were launched in October 2011.

TMW says a recent poll it conducted revealed 60% of advisers use an iPhone or an iPad.

The app is based on TMW’s ‘how much can be borrowed?’ calculator. It allows intermediaries to work out how much their client could borrow from TMW after entering the estimated purchase price/valuation and estimated rental income on a property.

Ian Andrew, managing director of intermediary sales at Nationwide, said: “The app has already proved popular with intermediaries